The glyphs are a bit underwhelming in my opinion. Which is a shame, because they could've actually done a lot more with them. I'm still waiting for my "Turns you into a Val'kyr that can fly" glyph, a la Zen Meditation.

I'm gonna use the sha one if it indeed removes the GCD on it, solely for DPS-gain/increased burst capabilities in PvP. The one with feathers should imo be able to be permanent if you spam heals, so 3 sec ish. And void shift one, indeed im gonna use it for trolling in raids.